blob: 2949d9ac74849cf80386e450db9bed4295462b09 [file] [log] [blame]
/* SPDX-License-Identifier: GPL-2.0 */
#ifndef BLK_MQ_H
#define BLK_MQ_H
#include <linux/blkdev.h>
#include <linux/sbitmap.h>
#include <linux/srcu.h>
#include <linux/lockdep.h>
#include <linux/scatterlist.h>
#include <linux/prefetch.h>
struct blk_mq_tags;
struct blk_flush_queue;
#define BLKDEV_MIN_RQ 4
typedef void (rq_end_io_fn)(struct request *, blk_status_t);
* request flags */
typedef __u32 __bitwise req_flags_t;
/* drive already may have started this one */
#define RQF_STARTED ((__force req_flags_t)(1 << 1))
/* may not be passed by ioscheduler */
#define RQF_SOFTBARRIER ((__force req_flags_t)(1 << 3))
/* request for flush sequence */
#define RQF_FLUSH_SEQ ((__force req_flags_t)(1 << 4))
/* merge of different types, fail separately */
#define RQF_MIXED_MERGE ((__force req_flags_t)(1 << 5))
/* track inflight for MQ */
#define RQF_MQ_INFLIGHT ((__force req_flags_t)(1 << 6))
/* don't call prep for this one */
#define RQF_DONTPREP ((__force req_flags_t)(1 << 7))
/* vaguely specified driver internal error. Ignored by the block layer */
#define RQF_FAILED ((__force req_flags_t)(1 << 10))
/* don't warn about errors */
#define RQF_QUIET ((__force req_flags_t)(1 << 11))
/* elevator private data attached */
#define RQF_ELVPRIV ((__force req_flags_t)(1 << 12))
/* account into disk and partition IO statistics */
#define RQF_IO_STAT ((__force req_flags_t)(1 << 13))
/* runtime pm request */
#define RQF_PM ((__force req_flags_t)(1 << 15))
/* on IO scheduler merge hash */
#define RQF_HASHED ((__force req_flags_t)(1 << 16))
/* track IO completion time */
#define RQF_STATS ((__force req_flags_t)(1 << 17))
/* Look at ->special_vec for the actual data payload instead of the
bio chain. */
#define RQF_SPECIAL_PAYLOAD ((__force req_flags_t)(1 << 18))
/* The per-zone write lock is held for this request */
#define RQF_ZONE_WRITE_LOCKED ((__force req_flags_t)(1 << 19))
/* already slept for hybrid poll */
#define RQF_MQ_POLL_SLEPT ((__force req_flags_t)(1 << 20))
/* ->timeout has been called, don't expire again */
#define RQF_TIMED_OUT ((__force req_flags_t)(1 << 21))
/* queue has elevator attached */
#define RQF_ELV ((__force req_flags_t)(1 << 22))
/* flags that prevent us from merging requests: */
enum mq_rq_state {
* Try to put the fields that are referenced together in the same cacheline.
* If you modify this structure, make sure to update blk_rq_init() and
* especially blk_mq_rq_ctx_init() to take care of the added fields.
struct request {
struct request_queue *q;
struct blk_mq_ctx *mq_ctx;
struct blk_mq_hw_ctx *mq_hctx;
unsigned int cmd_flags; /* op and common flags */
req_flags_t rq_flags;
int tag;
int internal_tag;
unsigned int timeout;
/* the following two fields are internal, NEVER access directly */
unsigned int __data_len; /* total data len */
sector_t __sector; /* sector cursor */
struct bio *bio;
struct bio *biotail;
union {
struct list_head queuelist;
struct request *rq_next;
struct gendisk *rq_disk;
struct block_device *part;
/* Time that the first bio started allocating this request. */
u64 alloc_time_ns;
/* Time that this request was allocated for this IO. */
u64 start_time_ns;
/* Time that I/O was submitted to the device. */
u64 io_start_time_ns;
unsigned short wbt_flags;
* rq sectors used for blk stats. It has the same value
* with blk_rq_sectors(rq), except that it never be zeroed
* by completion.
unsigned short stats_sectors;
* Number of scatter-gather DMA addr+len pairs after
* physical address coalescing is performed.
unsigned short nr_phys_segments;
unsigned short nr_integrity_segments;
struct bio_crypt_ctx *crypt_ctx;
struct blk_crypto_keyslot *crypt_keyslot;
unsigned short write_hint;
unsigned short ioprio;
enum mq_rq_state state;
refcount_t ref;
unsigned long deadline;
* The hash is used inside the scheduler, and killed once the
* request reaches the dispatch list. The ipi_list is only used
* to queue the request for softirq completion, which is long
* after the request has been unhashed (and even removed from
* the dispatch list).
union {
struct hlist_node hash; /* merge hash */
struct llist_node ipi_list;
* The rb_node is only used inside the io scheduler, requests
* are pruned when moved to the dispatch queue. So let the
* completion_data share space with the rb_node.
union {
struct rb_node rb_node; /* sort/lookup */
struct bio_vec special_vec;
void *completion_data;
int error_count; /* for legacy drivers, don't use */
* Three pointers are available for the IO schedulers, if they need
* more they have to dynamically allocate it. Flush requests are
* never put on the IO scheduler. So let the flush fields share
* space with the elevator data.
union {
struct {
struct io_cq *icq;
void *priv[2];
} elv;
struct {
unsigned int seq;
struct list_head list;
rq_end_io_fn *saved_end_io;
} flush;
union {
struct __call_single_data csd;
u64 fifo_time;
* completion callback.
rq_end_io_fn *end_io;
void *end_io_data;
#define req_op(req) \
((req)->cmd_flags & REQ_OP_MASK)
static inline bool blk_rq_is_passthrough(struct request *rq)
return blk_op_is_passthrough(req_op(rq));
static inline unsigned short req_get_ioprio(struct request *req)
return req->ioprio;
#define rq_data_dir(rq) (op_is_write(req_op(rq)) ? WRITE : READ)
#define rq_dma_dir(rq) \
(op_is_write(req_op(rq)) ? DMA_TO_DEVICE : DMA_FROM_DEVICE)
enum blk_eh_timer_return {
BLK_EH_DONE, /* drivers has completed the command */
BLK_EH_RESET_TIMER, /* reset timer and try again */
#define BLK_TAG_ALLOC_FIFO 0 /* allocate starting from 0 */
#define BLK_TAG_ALLOC_RR 1 /* allocate starting from last allocated tag */
* struct blk_mq_hw_ctx - State for a hardware queue facing the hardware
* block device
struct blk_mq_hw_ctx {
struct {
/** @lock: Protects the dispatch list. */
spinlock_t lock;
* @dispatch: Used for requests that are ready to be
* dispatched to the hardware but for some reason (e.g. lack of
* resources) could not be sent to the hardware. As soon as the
* driver can send new requests, requests at this list will
* be sent first for a fairer dispatch.
struct list_head dispatch;
* @state: BLK_MQ_S_* flags. Defines the state of the hw
* queue (active, scheduled to restart, stopped).
unsigned long state;
} ____cacheline_aligned_in_smp;
* @run_work: Used for scheduling a hardware queue run at a later time.
struct delayed_work run_work;
/** @cpumask: Map of available CPUs where this hctx can run. */
cpumask_var_t cpumask;
* @next_cpu: Used by blk_mq_hctx_next_cpu() for round-robin CPU
* selection from @cpumask.
int next_cpu;
* @next_cpu_batch: Counter of how many works left in the batch before
* changing to the next CPU.
int next_cpu_batch;
/** @flags: BLK_MQ_F_* flags. Defines the behaviour of the queue. */
unsigned long flags;
* @sched_data: Pointer owned by the IO scheduler attached to a request
* queue. It's up to the IO scheduler how to use this pointer.
void *sched_data;
* @queue: Pointer to the request queue that owns this hardware context.
struct request_queue *queue;
/** @fq: Queue of requests that need to perform a flush operation. */
struct blk_flush_queue *fq;
* @driver_data: Pointer to data owned by the block driver that created
* this hctx
void *driver_data;
* @ctx_map: Bitmap for each software queue. If bit is on, there is a
* pending request in that software queue.
struct sbitmap ctx_map;
* @dispatch_from: Software queue to be used when no scheduler was
* selected.
struct blk_mq_ctx *dispatch_from;
* @dispatch_busy: Number used by blk_mq_update_dispatch_busy() to
* decide if the hw_queue is busy using Exponential Weighted Moving
* Average algorithm.
unsigned int dispatch_busy;
/** @type: HCTX_TYPE_* flags. Type of hardware queue. */
unsigned short type;
/** @nr_ctx: Number of software queues. */
unsigned short nr_ctx;
/** @ctxs: Array of software queues. */
struct blk_mq_ctx **ctxs;
/** @dispatch_wait_lock: Lock for dispatch_wait queue. */
spinlock_t dispatch_wait_lock;
* @dispatch_wait: Waitqueue to put requests when there is no tag
* available at the moment, to wait for another try in the future.
wait_queue_entry_t dispatch_wait;
* @wait_index: Index of next available dispatch_wait queue to insert
* requests.
atomic_t wait_index;
* @tags: Tags owned by the block driver. A tag at this set is only
* assigned when a request is dispatched from a hardware queue.
struct blk_mq_tags *tags;
* @sched_tags: Tags owned by I/O scheduler. If there is an I/O
* scheduler associated with a request queue, a tag is assigned when
* that request is allocated. Else, this member is not used.
struct blk_mq_tags *sched_tags;
/** @queued: Number of queued requests. */
unsigned long queued;
/** @run: Number of dispatched requests. */
unsigned long run;
/** @numa_node: NUMA node the storage adapter has been connected to. */
unsigned int numa_node;
/** @queue_num: Index of this hardware queue. */
unsigned int queue_num;
* @nr_active: Number of active requests. Only used when a tag set is
* shared across request queues.
atomic_t nr_active;
/** @cpuhp_online: List to store request if CPU is going to die */
struct hlist_node cpuhp_online;
/** @cpuhp_dead: List to store request if some CPU die. */
struct hlist_node cpuhp_dead;
/** @kobj: Kernel object for sysfs. */
struct kobject kobj;
* @debugfs_dir: debugfs directory for this hardware queue. Named
* as cpu<cpu_number>.
struct dentry *debugfs_dir;
/** @sched_debugfs_dir: debugfs directory for the scheduler. */
struct dentry *sched_debugfs_dir;
* @hctx_list: if this hctx is not in use, this is an entry in
* q->unused_hctx_list.
struct list_head hctx_list;
* @srcu: Sleepable RCU. Use as lock when type of the hardware queue is
* blocking (BLK_MQ_F_BLOCKING). Must be the last member - see also
* blk_mq_hw_ctx_size().
struct srcu_struct srcu[];
* struct blk_mq_queue_map - Map software queues to hardware queues
* @mq_map: CPU ID to hardware queue index map. This is an array
* with nr_cpu_ids elements. Each element has a value in the range
* [@queue_offset, @queue_offset + @nr_queues).
* @nr_queues: Number of hardware queues to map CPU IDs onto.
* @queue_offset: First hardware queue to map onto. Used by the PCIe NVMe
* driver to map each hardware queue type (enum hctx_type) onto a distinct
* set of hardware queues.
struct blk_mq_queue_map {
unsigned int *mq_map;
unsigned int nr_queues;
unsigned int queue_offset;
* enum hctx_type - Type of hardware queue
* @HCTX_TYPE_DEFAULT: All I/O not otherwise accounted for.
* @HCTX_TYPE_POLL: Polled I/O of any kind.
* @HCTX_MAX_TYPES: Number of types of hctx.
enum hctx_type {
* struct blk_mq_tag_set - tag set that can be shared between request queues
* @map: One or more ctx -> hctx mappings. One map exists for each
* hardware queue type (enum hctx_type) that the driver wishes
* to support. There are no restrictions on maps being of the
* same size, and it's perfectly legal to share maps between
* types.
* @nr_maps: Number of elements in the @map array. A number in the range
* @ops: Pointers to functions that implement block driver behavior.
* @nr_hw_queues: Number of hardware queues supported by the block driver that
* owns this data structure.
* @queue_depth: Number of tags per hardware queue, reserved tags included.
* @reserved_tags: Number of tags to set aside for BLK_MQ_REQ_RESERVED tag
* allocations.
* @cmd_size: Number of additional bytes to allocate per request. The block
* driver owns these additional bytes.
* @numa_node: NUMA node the storage adapter has been connected to.
* @timeout: Request processing timeout in jiffies.
* @flags: Zero or more BLK_MQ_F_* flags.
* @driver_data: Pointer to data owned by the block driver that created this
* tag set.
* @tags: Tag sets. One tag set per hardware queue. Has @nr_hw_queues
* elements.
* @shared_tags:
* Shared set of tags. Has @nr_hw_queues elements. If set,
* shared by all @tags.
* @tag_list_lock: Serializes tag_list accesses.
* @tag_list: List of the request queues that use this tag set. See also
* request_queue.tag_set_list.
struct blk_mq_tag_set {
struct blk_mq_queue_map map[HCTX_MAX_TYPES];
unsigned int nr_maps;
const struct blk_mq_ops *ops;
unsigned int nr_hw_queues;
unsigned int queue_depth;
unsigned int reserved_tags;
unsigned int cmd_size;
int numa_node;
unsigned int timeout;
unsigned int flags;
void *driver_data;
struct blk_mq_tags **tags;
struct blk_mq_tags *shared_tags;
struct mutex tag_list_lock;
struct list_head tag_list;
* struct blk_mq_queue_data - Data about a request inserted in a queue
* @rq: Request pointer.
* @last: If it is the last request in the queue.
struct blk_mq_queue_data {
struct request *rq;
bool last;
typedef bool (busy_iter_fn)(struct blk_mq_hw_ctx *, struct request *, void *,
typedef bool (busy_tag_iter_fn)(struct request *, void *, bool);
* struct blk_mq_ops - Callback functions that implements block driver
* behaviour.
struct blk_mq_ops {
* @queue_rq: Queue a new request from block IO.
blk_status_t (*queue_rq)(struct blk_mq_hw_ctx *,
const struct blk_mq_queue_data *);
* @commit_rqs: If a driver uses bd->last to judge when to submit
* requests to hardware, it must define this function. In case of errors
* that make us stop issuing further requests, this hook serves the
* purpose of kicking the hardware (which the last request otherwise
* would have done).
void (*commit_rqs)(struct blk_mq_hw_ctx *);
* @get_budget: Reserve budget before queue request, once .queue_rq is
* run, it is driver's responsibility to release the
* reserved budget. Also we have to handle failure case
* of .get_budget for avoiding I/O deadlock.
int (*get_budget)(struct request_queue *);
* @put_budget: Release the reserved budget.
void (*put_budget)(struct request_queue *, int);
* @set_rq_budget_token: store rq's budget token
void (*set_rq_budget_token)(struct request *, int);
* @get_rq_budget_token: retrieve rq's budget token
int (*get_rq_budget_token)(struct request *);
* @timeout: Called on request timeout.
enum blk_eh_timer_return (*timeout)(struct request *, bool);
* @poll: Called to poll for completion of a specific tag.
int (*poll)(struct blk_mq_hw_ctx *, struct io_comp_batch *);
* @complete: Mark the request as complete.
void (*complete)(struct request *);
* @init_hctx: Called when the block layer side of a hardware queue has
* been set up, allowing the driver to allocate/init matching
* structures.
int (*init_hctx)(struct blk_mq_hw_ctx *, void *, unsigned int);
* @exit_hctx: Ditto for exit/teardown.
void (*exit_hctx)(struct blk_mq_hw_ctx *, unsigned int);
* @init_request: Called for every command allocated by the block layer
* to allow the driver to set up driver specific data.
* Tag greater than or equal to queue_depth is for setting up
* flush request.
int (*init_request)(struct blk_mq_tag_set *set, struct request *,
unsigned int, unsigned int);
* @exit_request: Ditto for exit/teardown.
void (*exit_request)(struct blk_mq_tag_set *set, struct request *,
unsigned int);
* @cleanup_rq: Called before freeing one request which isn't completed
* yet, and usually for freeing the driver private data.
void (*cleanup_rq)(struct request *);
* @busy: If set, returns whether or not this queue currently is busy.
bool (*busy)(struct request_queue *);
* @map_queues: This allows drivers specify their own queue mapping by
* overriding the setup-time function that builds the mq_map.
int (*map_queues)(struct blk_mq_tag_set *set);
* @show_rq: Used by the debugfs implementation to show driver-specific
* information about a request.
void (*show_rq)(struct seq_file *m, struct request *rq);
enum {
* Set when this device requires underlying blk-mq device for
* completing IO:
/* Do not allow an I/O scheduler to be configured. */
BLK_MQ_F_NO_SCHED = 1 << 6,
* Select 'none' during queue registration in case of a single hwq
* or shared hwqs instead of 'mq-deadline'.
/* hw queue is inactive after all its CPUs become offline */
#define BLK_MQ_FLAG_TO_ALLOC_POLICY(flags) \
#define BLK_ALLOC_POLICY_TO_MQ_FLAG(policy) \
((policy & ((1 << BLK_MQ_F_ALLOC_POLICY_BITS) - 1)) \
#define BLK_MQ_NO_HCTX_IDX (-1U)
struct gendisk *__blk_mq_alloc_disk(struct blk_mq_tag_set *set, void *queuedata,
struct lock_class_key *lkclass);
#define blk_mq_alloc_disk(set, queuedata) \
({ \
static struct lock_class_key __key; \
__blk_mq_alloc_disk(set, queuedata, &__key); \
struct request_queue *blk_mq_init_queue(struct blk_mq_tag_set *);
int blk_mq_init_allocated_queue(struct blk_mq_tag_set *set,
struct request_queue *q);
void blk_mq_unregister_dev(struct device *, struct request_queue *);
int blk_mq_alloc_tag_set(struct blk_mq_tag_set *set);
int blk_mq_alloc_sq_tag_set(struct blk_mq_tag_set *set,
const struct blk_mq_ops *ops, unsigned int queue_depth,
unsigned int set_flags);
void blk_mq_free_tag_set(struct blk_mq_tag_set *set);
void blk_mq_free_request(struct request *rq);
bool blk_mq_queue_inflight(struct request_queue *q);
enum {
/* return when out of requests */
BLK_MQ_REQ_NOWAIT = (__force blk_mq_req_flags_t)(1 << 0),
/* allocate from reserved pool */
BLK_MQ_REQ_RESERVED = (__force blk_mq_req_flags_t)(1 << 1),
/* set RQF_PM */
BLK_MQ_REQ_PM = (__force blk_mq_req_flags_t)(1 << 2),
struct request *blk_mq_alloc_request(struct request_queue *q, unsigned int op,
blk_mq_req_flags_t flags);
struct request *blk_mq_alloc_request_hctx(struct request_queue *q,
unsigned int op, blk_mq_req_flags_t flags,
unsigned int hctx_idx);
* Tag address space map.
struct blk_mq_tags {
unsigned int nr_tags;
unsigned int nr_reserved_tags;
atomic_t active_queues;
struct sbitmap_queue bitmap_tags;
struct sbitmap_queue breserved_tags;
struct request **rqs;
struct request **static_rqs;
struct list_head page_list;
* used to clear request reference in rqs[] before freeing one
* request pool
spinlock_t lock;
static inline struct request *blk_mq_tag_to_rq(struct blk_mq_tags *tags,
unsigned int tag)
if (tag < tags->nr_tags) {
return tags->rqs[tag];
return NULL;
enum {
u32 blk_mq_unique_tag(struct request *rq);
static inline u16 blk_mq_unique_tag_to_hwq(u32 unique_tag)
return unique_tag >> BLK_MQ_UNIQUE_TAG_BITS;
static inline u16 blk_mq_unique_tag_to_tag(u32 unique_tag)
return unique_tag & BLK_MQ_UNIQUE_TAG_MASK;
* blk_mq_rq_state() - read the current MQ_RQ_* state of a request
* @rq: target request.
static inline enum mq_rq_state blk_mq_rq_state(struct request *rq)
return READ_ONCE(rq->state);
static inline int blk_mq_request_started(struct request *rq)
return blk_mq_rq_state(rq) != MQ_RQ_IDLE;
static inline int blk_mq_request_completed(struct request *rq)
return blk_mq_rq_state(rq) == MQ_RQ_COMPLETE;
* Set the state to complete when completing a request from inside ->queue_rq.
* This is used by drivers that want to ensure special complete actions that
* need access to the request are called on failure, e.g. by nvme for
* multipathing.
static inline void blk_mq_set_request_complete(struct request *rq)
void blk_mq_start_request(struct request *rq);
void blk_mq_end_request(struct request *rq, blk_status_t error);
void __blk_mq_end_request(struct request *rq, blk_status_t error);
void blk_mq_end_request_batch(struct io_comp_batch *ib);
* Only need start/end time stamping if we have iostat or
* blk stats enabled, or using an IO scheduler.
static inline bool blk_mq_need_time_stamp(struct request *rq)
return (rq->rq_flags & (RQF_IO_STAT | RQF_STATS | RQF_ELV));
* Batched completions only work when there is no I/O error and no special
* ->end_io handler.
static inline bool blk_mq_add_to_batch(struct request *req,
struct io_comp_batch *iob, int ioerror,
void (*complete)(struct io_comp_batch *))
if (!iob || (req->rq_flags & RQF_ELV) || req->end_io || ioerror)
return false;
if (!iob->complete)
iob->complete = complete;
else if (iob->complete != complete)
return false;
iob->need_ts |= blk_mq_need_time_stamp(req);
rq_list_add(&iob->req_list, req);
return true;
void blk_mq_requeue_request(struct request *rq, bool kick_requeue_list);
void blk_mq_kick_requeue_list(struct request_queue *q);
void blk_mq_delay_kick_requeue_list(struct request_queue *q, unsigned long msecs);
void blk_mq_complete_request(struct request *rq);
bool blk_mq_complete_request_remote(struct request *rq);
bool blk_mq_queue_stopped(struct request_queue *q);
void blk_mq_stop_hw_queue(struct blk_mq_hw_ctx *hctx);
void blk_mq_start_hw_queue(struct blk_mq_hw_ctx *hctx);
void blk_mq_stop_hw_queues(struct request_queue *q);
void blk_mq_start_hw_queues(struct request_queue *q);
void blk_mq_start_stopped_hw_queue(struct blk_mq_hw_ctx *hctx, bool async);
void blk_mq_start_stopped_hw_queues(struct request_queue *q, bool async);
void blk_mq_quiesce_queue(struct request_queue *q);
void blk_mq_wait_quiesce_done(struct request_queue *q);
void blk_mq_unquiesce_queue(struct request_queue *q);
void blk_mq_delay_run_hw_queue(struct blk_mq_hw_ctx *hctx, unsigned long msecs);
void blk_mq_run_hw_queue(struct blk_mq_hw_ctx *hctx, bool async);
void blk_mq_run_hw_queues(struct request_queue *q, bool async);
void blk_mq_delay_run_hw_queues(struct request_queue *q, unsigned long msecs);
void blk_mq_tagset_busy_iter(struct blk_mq_tag_set *tagset,
busy_tag_iter_fn *fn, void *priv);
void blk_mq_tagset_wait_completed_request(struct blk_mq_tag_set *tagset);
void blk_mq_freeze_queue(struct request_queue *q);
void blk_mq_unfreeze_queue(struct request_queue *q);
void blk_freeze_queue_start(struct request_queue *q);
void blk_mq_freeze_queue_wait(struct request_queue *q);
int blk_mq_freeze_queue_wait_timeout(struct request_queue *q,
unsigned long timeout);
int blk_mq_map_queues(struct blk_mq_queue_map *qmap);
void blk_mq_update_nr_hw_queues(struct blk_mq_tag_set *set, int nr_hw_queues);
void blk_mq_quiesce_queue_nowait(struct request_queue *q);
unsigned int blk_mq_rq_cpu(struct request *rq);
bool __blk_should_fake_timeout(struct request_queue *q);
static inline bool blk_should_fake_timeout(struct request_queue *q)
test_bit(QUEUE_FLAG_FAIL_IO, &q->queue_flags))
return __blk_should_fake_timeout(q);
return false;
* blk_mq_rq_from_pdu - cast a PDU to a request
* @pdu: the PDU (Protocol Data Unit) to be casted
* Return: request
* Driver command data is immediately after the request. So subtract request
* size to get back to the original request.
static inline struct request *blk_mq_rq_from_pdu(void *pdu)
return pdu - sizeof(struct request);
* blk_mq_rq_to_pdu - cast a request to a PDU
* @rq: the request to be casted
* Return: pointer to the PDU
* Driver command data is immediately after the request. So add request to get
* the PDU.
static inline void *blk_mq_rq_to_pdu(struct request *rq)
return rq + 1;
#define queue_for_each_hw_ctx(q, hctx, i) \
for ((i) = 0; (i) < (q)->nr_hw_queues && \
({ hctx = (q)->queue_hw_ctx[i]; 1; }); (i)++)
#define hctx_for_each_ctx(hctx, ctx, i) \
for ((i) = 0; (i) < (hctx)->nr_ctx && \
({ ctx = (hctx)->ctxs[(i)]; 1; }); (i)++)
static inline void blk_mq_cleanup_rq(struct request *rq)
if (rq->q->mq_ops->cleanup_rq)
static inline void blk_rq_bio_prep(struct request *rq, struct bio *bio,
unsigned int nr_segs)
rq->nr_phys_segments = nr_segs;
rq->__data_len = bio->bi_iter.bi_size;
rq->bio = rq->biotail = bio;
rq->ioprio = bio_prio(bio);
if (bio->bi_bdev)
rq->rq_disk = bio->bi_bdev->bd_disk;
void blk_mq_hctx_set_fq_lock_class(struct blk_mq_hw_ctx *hctx,
struct lock_class_key *key);
static inline bool rq_is_sync(struct request *rq)
return op_is_sync(rq->cmd_flags);
void blk_rq_init(struct request_queue *q, struct request *rq);
int blk_rq_prep_clone(struct request *rq, struct request *rq_src,
struct bio_set *bs, gfp_t gfp_mask,
int (*bio_ctr)(struct bio *, struct bio *, void *), void *data);
void blk_rq_unprep_clone(struct request *rq);
blk_status_t blk_insert_cloned_request(struct request_queue *q,
struct request *rq);
struct rq_map_data {
struct page **pages;
int page_order;
int nr_entries;
unsigned long offset;
int null_mapped;
int from_user;
int blk_rq_map_user(struct request_queue *, struct request *,
struct rq_map_data *, void __user *, unsigned long, gfp_t);
int blk_rq_map_user_iov(struct request_queue *, struct request *,
struct rq_map_data *, const struct iov_iter *, gfp_t);
int blk_rq_unmap_user(struct bio *);
int blk_rq_map_kern(struct request_queue *, struct request *, void *,
unsigned int, gfp_t);
int blk_rq_append_bio(struct request *rq, struct bio *bio);
void blk_execute_rq_nowait(struct gendisk *, struct request *, int,
rq_end_io_fn *);
blk_status_t blk_execute_rq(struct gendisk *bd_disk, struct request *rq,
int at_head);
struct req_iterator {
struct bvec_iter iter;
struct bio *bio;
#define __rq_for_each_bio(_bio, rq) \
if ((rq->bio)) \
for (_bio = (rq)->bio; _bio; _bio = _bio->bi_next)
#define rq_for_each_segment(bvl, _rq, _iter) \
__rq_for_each_bio(, _rq) \
bio_for_each_segment(bvl,, _iter.iter)
#define rq_for_each_bvec(bvl, _rq, _iter) \
__rq_for_each_bio(, _rq) \
bio_for_each_bvec(bvl,, _iter.iter)
#define rq_iter_last(bvec, _iter) \
(>bi_next == NULL && \
bio_iter_last(bvec, _iter.iter))
* blk_rq_pos() : the current sector
* blk_rq_bytes() : bytes left in the entire request
* blk_rq_cur_bytes() : bytes left in the current segment
* blk_rq_err_bytes() : bytes left till the next error boundary
* blk_rq_sectors() : sectors left in the entire request
* blk_rq_cur_sectors() : sectors left in the current segment
* blk_rq_stats_sectors() : sectors of the entire request used for stats
static inline sector_t blk_rq_pos(const struct request *rq)
return rq->__sector;
static inline unsigned int blk_rq_bytes(const struct request *rq)
return rq->__data_len;
static inline int blk_rq_cur_bytes(const struct request *rq)
if (!rq->bio)
return 0;
if (!bio_has_data(rq->bio)) /* dataless requests such as discard */
return rq->bio->bi_iter.bi_size;
return bio_iovec(rq->bio).bv_len;
unsigned int blk_rq_err_bytes(const struct request *rq);
static inline unsigned int blk_rq_sectors(const struct request *rq)
return blk_rq_bytes(rq) >> SECTOR_SHIFT;
static inline unsigned int blk_rq_cur_sectors(const struct request *rq)
return blk_rq_cur_bytes(rq) >> SECTOR_SHIFT;
static inline unsigned int blk_rq_stats_sectors(const struct request *rq)
return rq->stats_sectors;
* Some commands like WRITE SAME have a payload or data transfer size which
* is different from the size of the request. Any driver that supports such
* commands using the RQF_SPECIAL_PAYLOAD flag needs to use this helper to
* calculate the data transfer size.
static inline unsigned int blk_rq_payload_bytes(struct request *rq)
if (rq->rq_flags & RQF_SPECIAL_PAYLOAD)
return rq->special_vec.bv_len;
return blk_rq_bytes(rq);
* Return the first full biovec in the request. The caller needs to check that
* there are any bvecs before calling this helper.
static inline struct bio_vec req_bvec(struct request *rq)
if (rq->rq_flags & RQF_SPECIAL_PAYLOAD)
return rq->special_vec;
return mp_bvec_iter_bvec(rq->bio->bi_io_vec, rq->bio->bi_iter);
static inline unsigned int blk_rq_count_bios(struct request *rq)
unsigned int nr_bios = 0;
struct bio *bio;
__rq_for_each_bio(bio, rq)
return nr_bios;
void blk_steal_bios(struct bio_list *list, struct request *rq);
* Request completion related functions.
* blk_update_request() completes given number of bytes and updates
* the request without completing it.
bool blk_update_request(struct request *rq, blk_status_t error,
unsigned int nr_bytes);
void blk_abort_request(struct request *);
* Number of physical segments as sent to the device.
* Normally this is the number of discontiguous data segments sent by the
* submitter. But for data-less command like discard we might have no
* actual data segments submitted, but the driver might have to add it's
* own special payload. In that case we still return 1 here so that this
* special payload will be mapped.
static inline unsigned short blk_rq_nr_phys_segments(struct request *rq)
if (rq->rq_flags & RQF_SPECIAL_PAYLOAD)
return 1;
return rq->nr_phys_segments;
* Number of discard segments (or ranges) the driver needs to fill in.
* Each discard bio merged into a request is counted as one segment.
static inline unsigned short blk_rq_nr_discard_segments(struct request *rq)
return max_t(unsigned short, rq->nr_phys_segments, 1);
int __blk_rq_map_sg(struct request_queue *q, struct request *rq,
struct scatterlist *sglist, struct scatterlist **last_sg);
static inline int blk_rq_map_sg(struct request_queue *q, struct request *rq,
struct scatterlist *sglist)
struct scatterlist *last_sg = NULL;
return __blk_rq_map_sg(q, rq, sglist, &last_sg);
void blk_dump_rq_flags(struct request *, char *);
static inline unsigned int blk_rq_zone_no(struct request *rq)
return blk_queue_zone_no(rq->q, blk_rq_pos(rq));
static inline unsigned int blk_rq_zone_is_seq(struct request *rq)
return blk_queue_zone_is_seq(rq->q, blk_rq_pos(rq));
bool blk_req_needs_zone_write_lock(struct request *rq);
bool blk_req_zone_write_trylock(struct request *rq);
void __blk_req_zone_write_lock(struct request *rq);
void __blk_req_zone_write_unlock(struct request *rq);
static inline void blk_req_zone_write_lock(struct request *rq)
if (blk_req_needs_zone_write_lock(rq))
static inline void blk_req_zone_write_unlock(struct request *rq)
if (rq->rq_flags & RQF_ZONE_WRITE_LOCKED)
static inline bool blk_req_zone_is_write_locked(struct request *rq)
return rq->q->seq_zones_wlock &&
test_bit(blk_rq_zone_no(rq), rq->q->seq_zones_wlock);
static inline bool blk_req_can_dispatch_to_zone(struct request *rq)
if (!blk_req_needs_zone_write_lock(rq))
return true;
return !blk_req_zone_is_write_locked(rq);
static inline bool blk_req_needs_zone_write_lock(struct request *rq)
return false;
static inline void blk_req_zone_write_lock(struct request *rq)
static inline void blk_req_zone_write_unlock(struct request *rq)
static inline bool blk_req_zone_is_write_locked(struct request *rq)
return false;
static inline bool blk_req_can_dispatch_to_zone(struct request *rq)
return true;
# error "You should define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE for your platform"
void rq_flush_dcache_pages(struct request *rq);
static inline void rq_flush_dcache_pages(struct request *rq)
#endif /* BLK_MQ_H */